Mauna Kea Climb tire choice and logistics

Hi All,

Doing the climb in late Feb. As you all know there’s a 7+ mile gravel segment of deep fine sand. So tire choice is critical. I don’t want to swap wheels or bikes.

What tires you guys recommend, for fast rolling over the whole climb (paved and gravel)?

Are the Specialized Pathfinder 42 a good choice?

Do I need thread + Tire volume ?

How about the RH Sinequalme Pass 44cm slicks?

Thanks a lot!

1 Like

I havent ridden that, but I’ve driven it. I dont think that area really gets any rain, so I’d be leaning towards the slick rene herses, those are probably perfect.

Edit: oh wow lol. I just looked it up. Yea that mountain gets 7mm of rain. A YEAR lol. It’s going to be i’m sure exactly like it was when I drove it. Dry, dusty, super hard pack, some smaller loose rocks scattered over the top.

My wife and I did the stargazing tour and took a 4x4 sprinter to the top. I don’t know how sandy it is, but it’s more like loose degraded cinders than sand. The wheel tracks from the 4x4’s going up should give you a somewhat packed track to ride in, but a 42-45 would be a good idea.

I might go for a Maxxis rambler or GK SK. something that rolls well on pavement, but has enough tread to bite on the loose stuff when you hit it.

Depending on where you’re coming from riders start to struggle at the visitor’s center (9k ft) which is also where the pavement (mostly) ends. Last mile or two is actually paved to keep dust down around the telescopes.

Also be advised that you need to have someone in a 4x4 waiting for you at the top.

If I were going to do the full climb from sea level to observatories, I’d go from the Hilo side as there’s a HUGE shoulder all the way to the turn off of Saddle Back.

1 Like

I looked up pics, and it jives with my memory. Looks pretty washboardy, with some solid rocky chunks. The only issue with the RH might be slicing a sidewall.

1 Like

Rambler 60tpi with silk shield, GK SK+. Last place I’d like to have to do tire repair is while gasping for breath on a volcano…

1 Like

I did MK in October. I ran GP5000s in 28. Honestly, almost regardless of your tire choice, you’re gonna have a bad time on the gravel. I think the prime tire is something like a 32 mm slick gravel/CX tire. Most of the climb is on pavement, and you don’t want to make your life miserable for that. The most important things for the climb are:

  1. Pacing
  2. Nutrition
  3. Gearing
  4. System weight
  5. Tire choice, with an eye toward rolling resistance

Have a support vehicle to feed you and refill your water. Ideally, bring someone on an eMTB from the Visitor Information Station up to the top with you to carry more fuel and your layers. It is COLD on the top and the descent back down to the VIS is even colder. If you have access to a 4x4 to bring your support to the summit, even better. Please do not try to descend back to the ocean.

Because of the gearing choices available to me, I used my rim brake road bike (<7 kg) geared to 50/34 and 11/34. Thought I was going to have to stick with 11/30 in the back until I realized the day before I left that the new DA 12 speed RD can accommodate 34t, so I ripped my Ultegra cassette off my gravel bike. I set up my GP5ks tubeless at 80 psi to the VIS, then dropped them to 60 psi for the rest.

If I had to do it again and were attempting speed, I’d rent a short travel full squish XC bike and switch to it at the VIS to take to the summit.

It’s more like 4.5 miles of unpaved nonsense with 2500 feet of gain. I’ll post a video later tonight.


@The_Conductor sounds like you had a good time. MK is on my bucket list, would you recommend!?

Gravel starts right after the visitors center at 9,200 feet, then you go to almost 12k on gravel before it switches back to tarmac? Just don’t recall where that switch happened, but either way when you hit 9k, you’re gonna feel the burn.

I just remember being at the summit, walking down to take a picture of one observatory, then walking back up the hill to the van and was VERY woozy after. That was the same year I was deep into training for Unbound, so I had the fitness, but not for that altitude.

By all means go for it! That’s some serious bragging rights going from sea to summit. (be ready to call it a day when you summit though, cause you’re likely to be shot)


Is 4x4 strictly necessary?. I’m renting a suburban, the 4x4 is $250 more.

This is precisely what I want to avoid.

I live in the high country. I’ll be ok :wink:

How bad can it be?. The only issue is if the gravel is sandy. Please elaborate.

1 Like

It’s worth doing once, maybe more.

The rangers at the VIS will not let you drive beyond the VIS without a 4x4.

It is more elegant to ride one bike (which is why I did it). It is more enjoyable to ride two. The other option that splits the difference is a gravel bike/road bike with reasonable clearance with two wheel sets. Or, as I said, something in the 32 mm range with some grip. My rim brake roadie is tight enough as it is with 28s, so this wasn’t an option for me.

The issue is that you have to burn a ton of matches to just stay upright (or get back on your bike if you come off) while riding 11% grade with portions of >15% at >11,000 feet of elevation when you’re coming from sea level. You also don’t know what condition the road will be in because they periodically regrade it. That said, it is the volcanic equivalent of sandy. Torque too much to push through something and you’ll spin out.

This isn’t going to do it justice:

A modicum of fitness is obviously a prerequisite for this. FWIW, I’m 31 and 4.8-4.9 W/kg.


Did it on the 44mm Rene Herse slicks. In the winter it likely will graded almost daily, expect a lot of loose patches.

4x4 is required, they check, and will make you demonstrate that you can operate it. I highly suggest you go this route, I don’t recommend attempting the descent.

Late February is gonna be dicy. You will need to be super flexible on timing on an attempt and even then it might not work out. I did it same timeframe this year(2023) the day I went up was the ONLY day on our 9 days there that the road was open above the Visitor Center.

I also got stuck at the visitor center for 2 hours as it took them longer than planned to reopen the road after some overnight snow.

Literally the day after they received snow down to almost 8500’!

The climb to the access road is actually pretty tame, as soon as you’re on the access road is when it gets hard.

I was 35 and about 4wkg, I used my 50t on the cassette almost exclusively after the visitor center(30t chainring)


Nah, nothing will be that hard on tires( watch out for the road debris on the paved shoulder on the saddle rd though, I’ve never come across as much broken glass on the road as I have riding in Hawaii)


Look like SoCal style “gravel”? Volume is your friend. Note that sand racing bikes run 50c + slicks (g-one speed). I’d look at the G-One RS in 45mm because it has a meaningful side lug (are there any corners on your return?). If it’s full beach, MTB tire sizes.
Most of the fast 45-47mm tires should work as knobs won’t do much. If you have 650b wheels it might make sense for stand over height.

I wouldn’t go to the hassle of getting RH tires - a GK SS or SK will do the same thing. I would go to BRR and look at actual width of the tires - note they use a narrow rim.

Are you going to bring two sets of tires on this trip? If so, test mount them both and have the harder to mount tire preinstalled, then risk the easy mount tires (bring tubes!).

1 Like

My amazing wife did it in January of last year on Gravel King 32s. However, she was stopped by an incoming storm at the visitor’s center. I’d link to Strava, but I think hers is private.

Probably could’ve been a little faster on that portion with her dedicated climbing wheels and road tires, but she still cruised – ~4 hours to the visitor’s center, I think.

That climb has to be a bitch. My rented jeep nearly coughed up a lung getting to the top.

That sounds downright dreamy for this climb :joy:

It’s the most wrecked I’ve ever been after a single day athletic endeavor. I couldn’t eat dinner–couldn’t even sit in the restaurant. I went outside and laid on a grass median in the parking lot while my partner ate. Then went to bed before 7pm. It’s not the longest or overtly most miserable thing that I’ve done, but I think the combination of extreme altitude changes and sun exposure beats the snot out of you more than you realize.


Given that the gravel section accounts for ~7% of the ride, I would prioritize a tire that is fast and efficient on pavement that is just barely good enough for that gravel section. Zero reason to go any wider than 38-40mm(I ran 44’s because I had them and I wasn’t interested in buying a tire for a one off ride)


friends(that are clueless about this climb) were giving me shit for that setup. I’d say I had the last laugh, but I’m still the one that had to climb it :rofl:


This x10000000. I was afraid of blowing myself up before I even got to the gravel by riding a setup optimized for the gravel.


Yea. Honestly 32mm gp5000 might be fantastic.